1. Field of the Invention
The invention relates generally to an apparatus for collecting particles and vapor for detection applications.
2. Description of the Prior Art
Biocollectors can be used to collect airborne particles, including biological warfare agents. Such agents in their weaponized state may have particles sizes of only 5+/−4 microns, achieved by milling the biomaterial. Material in this size range can stay airborne for considerable periods and transport over wide areas through airflow. Prior biocollectors for such particles weighed about 10 pounds and required significant power to operate. They required relatively large volumes of processing solutions, and added a large size burden to biodetector technologies, which have the potential to be miniaturized through applications of MEMS and microfluidics. This miniaturization has been stymied by the lack of a miniature bioparticle collector.
Prior particle collectors typically incorporate a relatively high pressure drop across the device to collect the smallest particles. For example, a HEPA filter may collect micron size particles, but a high pressure drop across the filter is required to generate the desired airflow rate. This cannot be generated with miniaturized equipment without expending considerable amounts of power and operating equipment under duress.
Call et at., U.S. Pat. No. 6,267,016 discloses a combined impact collector and fan. The fan is a plate with raised veins. There are no open areas in the plate through which air can flow. All sampled air must flow through a narrow gap between the collector and the house, which results in a high pressure drop.
There is a need for a bioparticle collector that is small and lightweight, consumes little power, and allows for the use of small volumes of solution in processing collected material. Such a collector would be useful in a miniature biodetector.